Recently, the ink-jet recording has been applied to recording has been applied to various printing fields such as photography, various kinds of printings, and especially printing such as marking and color filters because the ink-jet recording method can produce an image simply and at low cost.
Particularly, an image quality almost equal to a silver halide photograph can be obtained by means of: (i) a recording apparatus which enables to jet and to control a fine dot; (ii) an ink having improved properties of color reproduction area, durability, and jetting property; and (iii) an exclusive use sheet in which the absorptivity of the ink, coloring property of the coloring material, surface glossiness are greatly increased.
The increase of the image quality of today's ink-jet recording system is attained only when all of the recording apparatus, ink, and exclusive use sheet are present.
However, for the ink-jet system which requires exclusive use sheets, the kinds of the recording medium are limited and the cost increase of the recording medium becomes a problem. Accordingly, many trials have been made to record onto the recording medium different from the exclusive use sheet using the ink-jet method. They are, for example, a phase change ink-jet system using a solid wax ink at a room temperature, a solvent type ink-jet system using a quick dry type organic solvent as a main component, or a UV ink-jet system in which a cross-linkage is formed by an ultra violet (UV) ray after recording.
Among the above-mentioned trials, the UV ink-jet system has a lower degree of smell than the solvent type ink-jet system. The UV ink-jet system has been paid attention in recent years by considering its rapid drying property and a capability to record on a non-ink absorptive medium. Listed examples are shown, in Japanese Patent Publication Open to Public Inspection (hereafter is called, JP-A) No. 5-54667, JP-A No. 6-200204, and Japanese Translated PCT Patent Publication No. 2000-504778, the ultraviolet ray curing type ink-jet ink is disclosed.
However, even when these inks are used, it is difficult to form the highly minute image onto various recording materials because a diameter of a dot reached on the recording material is largely changed due to the kind of the recording material or the working environment.
For example, as the ultraviolet ray curing type ink, there are a radical polymerization type ultraviolet ray curing type ink comprising an acrylic component as a main composition, and a cation polymerization type ultraviolet ray curing type ink. The radical polymerization type ultraviolet ray curing type ink has a problem in which, in its polymerization mechanism, the curing property is decreased because it is subjected to the oxygen inhibition action under the environment in which the oxygen is present. On the one hand, the cation polymerization type ultraviolet ray curing type ink is not subjected to the oxygen inhibition action. However, due to the nature of the polymerization reaction, there is a problem in which it is easily subjected to the influence of water, and the dark reaction is easily advanced, resulting a problem of low shelf keeping stability.